More than 100 countries have signed a commitment to reduce their methane emissions by at least 30 per cent from 2020 levels by 2030 – but the pledge came without participation from the top three emitters: China, Russia and India. The Global Methane Pledge, initiated on Tuesday at the COP26 summit in Glasgow, Scotland, covers countries which emit nearly half of global methane emissions and make up 70 per cent of global GDP. It was first proposed by the United States and the European Union in September and supported by some top emitters, including Brazil, Indonesia, Pakistan and Argentina. Methane is the second-most abundant human-caused greenhouse gas, after carbon dioxide. It has an atmospheric lifetime of roughly a decade and a strong influence on the climate. Over a 20-year period, methane can warm the atmosphere 80 times more powerfully than carbon dioxide. Reducing methane emissions also helps to improve air quality since it is a precursor to ground-level ozone, a dangerous air pollutant. Countries recognised in the pledge that significant reductions in methane emissions must be achieved globally by 2030 if the world is to achieve the Paris Agreement goal of keeping global warming well below 2 degrees Celsius, while pursuing efforts to limit such warming to 1.5 degrees. Successful institution of the pledge would help reduce global warming by at least 0.2 degrees Celsius by 2050, the COP26 statement said. Methane accounts for 17 per cent of global greenhouse gas emissions from human activities, particularly from three sectors – energy, agriculture and waste. In the energy sector, which accounts for more than a third of global methane emissions, emissions occur during oil and gas extraction, processing and distribution, as well as coal mining. The Global Methane Assessment report released by the United Nations Environment Programme in May found that currently available measures could reduce methane emissions from these major sectors by as much as 45 per cent this decade. The mitigation potential in different sectors varies among countries. For instance, the report noted, the largest potential in Europe and India is in the waste sector, while in China, the largest potential for reduction comes from coal production followed by livestock. Xi Jinping makes ‘big mistake’ by not showing up at COP26, Biden says China, the world’s largest country with human-caused methane emissions, did not join the pledge. At a press conference on Wednesday, Chinese foreign ministry spokesman Wang Wenbin did not directly explain why China did not join the pledge but said developing countries generally had weak basic data and lacked monitoring technologies and effective measures. But he added that China would increase its efforts to control non-carbon dioxide greenhouse gases – including methane and hydrofluorocarbons (HFCs), as laid out in the country’s 14th economic and social development plan through 2025. Relevant departments are formulating and implementing policies and measures to control emissions in industry, agriculture and waste disposal, Wang said. In its updated emissions reduction commitments, or Nationally Determined Contributions (NDCs), submitted to the United Nations last week, China said it would implement an action plan to step up control of key non-CO2 greenhouse gas emissions. Climate envoy Xie Zhenhua told a financial forum in July that China’s goal of achieving carbon neutrality by 2060 included non-CO2 greenhouse gases, but the country does not have near-term targets to reduce them. The plan for China to reach peak carbon emissions by 2030, released last week by the State Council, does not include any targets for the reduction of non-CO2 emissions. China’s CO2 emissions 9 per cent higher than pre-pandemic levels in 2021 first quarter According to a study led by scientists at Peking University last month, human-caused methane emissions in China increased by 40 per cent in the 2000s, contributing to 16 per cent of global anthropogenic emissions. The study noted that China’s human-caused methane emissions stabilised over the past decade, mainly due to stabilised coal production. Meanwhile, rising global temperatures are potentially enhancing the release of methane from natural sources, especially in the cryospheric regions – areas where water is in its solid form of ice or snow. A study by Chinese researchers in Nature in May found that high-elevation rivers on the Tibetan Plateau are major sources of methane delivery into the atmosphere. Maria Pastukhova, an energy analyst at the climate change think tank E3G, said the next step will be to win the commitment of the top emitters by next year’s COP27 conference. “The pledge, made by countries emitting half the world’s methane, is a positive and a long-overdue step forward, putting the second-biggest human-made cause of global warming in the spotlight,” she said. “Before COP27, the pledge must get the top three emitters – China, Russia and India – on board, supported by transparent governance and monitoring mechanisms.” Ani Dasgupta, president of the World Resources Institute, a global research organisation based in Washington, called on countries to increase their actions. “The next step is for countries to put the pledge in motion with serious policies across agriculture, energy and waste. Solutions to tackle methane are readily available, cost-effective and bring wins for climate and development,” he said. Teng Fei, deputy director of Tsinghua University’s Energy Environment Economy Institute, said weak basic data and the difficulty of reducing 30 per cent of methane emissions by 2030 were the main reasons China did not join the pledge. “We are not quite sure about the basis of some non-CO2 greenhouse gases and the uncertainty is relatively large. It is not quite serious to set an absolute emissions reduction target on this basis.” Teng said it was relatively difficult for China to achieve the target of a 30 per cent reduction in methane emissions by 2030 because of the country’s style of agriculture. “The top two sources of China’s methane emissions are coal production and agriculture. Despite China’s coal production declining, the methane emissions from abandoned coal mines are still unclear. And unlike the Western countries, China’s livestock and paddy fields are owned by small households, which makes reducing methane emissions more difficult.”